AP EAPCET (Engineering) Work, Energy and Power — practice questions
94 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice AP EAPCET (Engineering) Work, Energy and Power in the app →Work done by a constant force $\vec{F}$ when the body moves through displacement $\vec{s}$ is:The kinetic energy of a body of mass $m$ moving with speed $v$ is:The elastic potential energy stored in a spring of spring constant $k$ when stretched by displacement $x$ is:The work-energy theorem states that the net work done on a body equals:A 50 N force acts at right angles to a body's displacement. Work done?Work done on a load held steadily on a lifter's shoulder isWork done by a friction force that opposes the motion isThe kilowatt hour (kWh) on an electricity bill is a unit ofOne kilowatt hour equals how many joules?Kinetic energy is best described as aThe spring constant k is measured inA stiff spring is one that hasWhich of these forces is non-conservative?In every kind of collision, which quantity is conserved?Moon in a perfectly circular orbit: work done by Earth's gravity isFor gravitational PE mgh near Earth, the zero is usually atFor a spring, the zero of potential energy is at theThe work-energy theorem relates net work to the change inThe watt is the same as oneWhich steam-engine innovator gave his name to the unit of power?Which of these is a vector, not a scalar?Kinetic energy of a 2 kg body moving at 3 m/s isA 10 N force moves a body 5 m along its own direction. Work done?A block glides on a smooth desk. Work done by its weight isYou push hard against a rigid brick wall. Work done on the wall isA 1 kg mass is 10 m above the ground. Its PE is (g = 10 m/s^2)Which expression gives the dimensions of work?The instantaneous power of a force F on a body of velocity v isA machine does 3000 J of work in 10 s. Its average power isIf the speed of a body is halved, its kinetic energy becomesIf the mass doubles at the same speed, the kinetic energyA 4 kg body has 50 J of kinetic energy. Its speed isNet work done on a body is zero. Its kinetic energyA 1000 kg car going 10 m/s is braked to rest. Work done on car?A 5 N friction force opposes a body that moves 4 m. Work by friction?A cyclist skids 10 m against a 200 N stopping force. Work by road?A 20 N force at 60 degrees to the displacement moves a body 10 m. Work done?A 2 kg body rises 5 m. Work done by gravity? (g = 10 m/s^2)A body falls through height h. Work done by gravity isA 50 kg load is lifted 10 m in 5 s. Power needed? (g = 10 m/s^2)A motor lifts 100 kg at a steady 2 m/s, no friction. Power? (g = 10)A 750 W motor runs. In horse-power this is aboutA motor of 1492 W equals how many horse-power?A 2 kW heater runs for 3 hours. Energy consumed?A ball is dropped from 20 m (g = 10). Speed on hitting ground?A stone falls freely from 5 m (g = 10). Speed at the ground?A ball is thrown up at 20 m/s. Max height? (g = 10, no drag)A block slides from rest down a smooth 1.8 m slope. Speed? (g = 10)For a freely falling body, which quantity stays constant?A spring with k = 200 N/m is compressed 0.1 m. Energy stored?A spring is stretched twice as far. Its stored energy becomesA spring has k = 500 N/m. Force for 0.04 m extension?Hooke's law for a spring isA spring with a small k is calledA 2 kg body at 6 m/s sticks to a 4 kg body at rest. Final speed?2 kg at 6 m/s sticks to 4 kg at rest. Kinetic energy lost?In a head-on elastic hit between equal masses, with one at rest, the moverEqual masses collide elastically head-on, target at rest, mover at 4 m/s. Target speed after?A collision where deformation is only partly relieved isWhich quantity can change in an inelastic collision?The work-energy theorem is a scalar form ofConservation of mechanical energy follows from the WE theorem forPotential energy can be defined only forIn the WE theorem, the work that equals the change in KE is done by theA 1 g raindrop falls 1 km, landing at 50 m/s (g = 10). Work by air resistance?The centripetal force in uniform circular motion doesWork done by gravity as a stone rises vertically isWork is positive when force and displacement make an angle ofElectricity bills record consumption inWork done per unit time is calledA stretched spring can do work on release because it storesThe gravitational PE of a body turns into kinetic energy when itFor a conservative force, the change in K + V equalsA pendulum bob has maximum kinetic energy atWork in physics needs both force andA spring of constant k, extended by x, stores energyA 1800 kg lift rises at 2 m/s against 4000 N friction. Motor power? (g = 10)A motor delivers 44000 W. In horse-power this is nearlyA 4 kg body moves at 3 m/s. Its kinetic energy isWork of 100 J is done in 2 s. Average power?How many joules are in one kilowatt hour (kWh)?A 100 W bulb burns for 10 hours. How much energy does it use?For a conservative force in one dimension, the force F(x) is related to the potential energy V(x) by:Why can no potential energy be assigned to friction?After a completely inelastic collision, the two bodies:Which quantity is conserved in every type of collision of an isolated system?During an elastic collision, the kinetic energy of the system at each instant of contact is:A motor pulls with a force of 22000 N at a steady 2 m/s. What power does it supply?After which inventor is the SI unit of power named?Total mechanical energy of a body stays constant provided the only forces acting on it are:The work-energy theorem holds in which frames of reference?Power, like work and energy, is what kind of physical quantity?The potential energy of a body under a conservative force is always fixed only up to:Horse-power is still commonly used to describe the output of: