Mechanics | Relativity Answers

A bus traveling from El Paso Texas to an area in chihuahua Mexico in 5 h with an average velocity of 74km/h to the south. What is the bus's displacement? Answer in units of km

A car is traveling at 20m/s.The brakes are applied, producing a constant deceleration of 4m/s2 for 3 seconds.Then the brakes are released and the car continues to move with constant velocity.How far has the car traveled
a)Three seconds after the brakes began to be applied,
b)five seconds after the brakes began to be applied

a stationary object is released from a point P at a distance 3R from the centre of the moon which has radius R and mass M. Whiich of the following gives the speed of the object on hitting the moon?
1. (2GM/3R)^1/2
2. (4GM/3R)^1/2
3. (GM/3R)^1/2
4. (GM/R)^1/2

The position x of a particle moving along x axis at time(t) is given by equation t=x^1/2+2,where x is un metres and t in seconds. Find the work done by force in first 4 seconds.
(1)Zero
(2)2
(3)4
(4)8
All are in Joules.

A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude P. The instantaneous velocity of this car is proportional to
(1)t^2P
(2)t^1/2
(3)t^-1/2
(4)t/m^1/2

A ball is released from top of tower. The ratio of work done by force of gravity in first,second and third second of motion of ball is
(1)1:2:3
(2)1:4:9
(3)1:3:5
(4)1:5:3

The amount of work done in pumping the water out of a cubical vessel of height 1m is nearly(Taking g=10m/sec^2)
(1)5000
(2)10000
(3)5
(4)10
All options are in Joules.

a man across a 90 m long straight track with a uniform acceleration in 6 s.if his initial velocity is 3m/s, then he leaves the track with velocity

why the length of a simple pendulum decrease in winter and increase in summer?? basically we know length is unchanged.but whats the reason for this change? please explain with examples

What is the cost to operate a 100 W lamp continuously for 1 week when the power utility rate is 20
cents/kWh?