Mechanics | Relativity Answers

Calculate the volume of a rectangular block in cubic meter, cubic cm. and cubic ft. that has length of 33 cm and has a width of .89ft and height of 0.20 meter.

according to Newtons 3rd law of motion every force is accompanied by an equal and opposite force .How can a movement ever takes place?

an asteroid is 3 times as far from the sun as the earth. what is it's period in earth years?

A 25 newton force applied on an object moves it 50 meters. The angle between the force and displacement is 40.0°. What is the value of work being done on the object

a merry-go-round of 10 m radius with children sitting on it,is revolving at the rate of 1 revolution per minute. calculate the velocity of the children sitting on it?

A body covers 4m in the 3rd second and 12m in the 5th second . If the motion is uniformly accelerated . How far will it travel the next 3second

bucket full of water has 4 holes punctured in it vertically down outside of bucket, top to bottom. does escaping water through holes vary in pressure?

Assuming zero friction, what is the iniital velocity of a projectile that is fired straight up from the ground and takes 8 seconds to hit the ground.

an engine absorbs 2000J of heat from a hot reservoir and expels 750J to a cold reservoir during each operating circle.what is the efficiency of the engine and how much work is done during the circle?

A bird flies in the east direction with a speed of 5 ms−1. The wind is blowing towards north at a
speed of 3 ms−1. Determine the relative velocity of the bird with respect to the wind. Draw
appropriate diagram for solving the problem.
(b) A plane is flying with a constant speed along a straight line at an angle of 30° with the
horizontal. The weight of the plane is 80, 000 N and its engine provides a thrust of 100, 000 N in
the direction of flight. Two additional forces are exerted on the plane: the lift force perpendicular
to the plane’s wings, and the force due to air resistance opposite to the direction of motion. Draw
the free-body diagram showing all forces on the plane. Determine the lift force and the force due
to air resistance. (2 + 4)
2. A bus is moving downhill at a slope of 5° on a rainy day. At the moment when the speed of the
bus is 30 km h−1, the driver spots a deer 30 m ahead. He applies the brakes and comes to a stop.
The deer is paralyzed by fear and does not move. Will the bus stop before reaching it or will it hit
the deer? Do relevant calculations and draw appropriate force diagram. Take the coefficient of
kinetic friction to be μk = 0.26. (10)
3. Derive an expression relating impulse and linear momentum. In a safety test, a car of mass 1000
kg is driven into a brick wall. Its bumper behaves like a spring (k = 5 × 106 Nm−1) and is
compressed by a distance of 3 cm as the car comes to rest. Determine the initial speed of the car.