Mechanics | Relativity Answers

A projectile shot at an angle of 60 degrees above the horizontal strikes a wall 25 m away at a point 16 m above the level of projection.What is the magnitude of the velocity with which the projectile hits the wall ?

a)25.44 m/s

b)21.11 m/s

c)11.62 m/s

d)14.63 m/s

A cart is moving horizontally along a straight with constant speed of 30 m/s.A projectile fired from the moving cart in such a way that it will return to the cart after the cart has moved 80 m.At what speed(relative to the cart)and at what angle (to the horizontal) must the projectile be fired?

a)35.8 m/s at 24 degrees

b)38.6 m/s at 54 degrees

c)27.2 m/s at 35 degrees

d)24.3 m/s at 44 degrees

An object is thrown upward from the edge of a tall building with a velocity of 20 m/s. Where will the object be 5 s after it is thrown? take g=10ms-2

a)25 m above the top of the building

b)22 m below the top of the building

c)25 m below the top of the building

d)22 m above the top of the building

which of the following physical quantities is an example of cross product?

a)Work

b)Moment

c)Power

d)Momentum

A projectile is fired with velocity 20ms^-1 at angle 60 to the horizontal . Determine the components of the velocity at maximum height

The 100 gram puck moves at constant speed on a frictionless air table. It is tied to a central post, which causes it to move in a perfect circle. A student with a stopwatch determines that the puck takes 2.5 seconds to complete 5 revolutions.
A. What is the puck's period, T?
B. If the string is 15 cm long, how fast is the puck moving?
C. Determine the acceleration of the puck. In what direction is it accelerating?
D. Determine the net force on the puck.
E. Assume the string can only withstand 5 N of force. If the puck was moving twice the speed would the string break? Justify your answer.

Given that F=30units directed north_east.Find the magnitude and direction of 2F

A pipe contains a gradually tapering section where the diameter decreases from 400 mm to 250 mm. The pipe contains an incompressible fluid of density 1000 kgm−3 and runs full. If the flow velocity is 2 ms−1 in the smaller diameter, determine:
a) the velocity in the larger diameter
b) the volume flow rate
c) the mass flow rate.

If light travels at 3 · 108 m/s and its frequency is 6 · 1015 Hz, then its wavelength is:


10 · 107 m
5 · 10-8 m
5 · 10-7 m
10 · 10-7 m

if an object is in air from point A of earth at height iof 15000 ft at 90 degree in air after 12 hour when cobdy come back to earth what will be its location?is its location same? why?