M = 30 g = 0.03 kg, the mass of the bullet
v = 500 m/s, the velocity of the bullet
By definition, the KE (kinetic energy) of the bullet is
KE = (1/2)*m*v²
= 0.5*(0.03 kg)*(500 m/s)² = 3750 J
Because the bullet comes to rest, the change in mechanical energy is 3750 J.
The work done by the wall to stop the bullet in 12 cm is
W = (1/2)*(F N)*(0.12 m) = 0.06F J
If energy losses in the form of heat or sound waves are ignored, then
W = KE.
That is,
0.06F = 3750
F = 62500 N = 62.5 kN
Answer:
(a) 3750 J
(b) 62.5 kN
Answer:
Velocity of airplane is 500 km/h
Velocity of wind is 40 km/h
Explanation:
= Velocity of airplane in still air
= Velocity of wind
Time taken by plane to travel 1150 km against the wind is 2.5 hours

Time taken by plane to travel 450 km against the wind is 50 minutes = 50/60 hours

Subtracting the two equations we get

Applying the value of velocity of wind to the first equation

∴ Velocity of airplane in still air is 500 km/h and Velocity of wind is 40 km/h
Answer:
Increasing its charge
Increasing the field strength
Explanation:
For a charged particle moving in a circular path in a uniform magnetic field, the centripetal force is provided by the magnetic force, so we can write:

where
q is the charge
v is the velocity
B is the magnetic field
m is the mass
r is the radius of the orbit
The period of the motion is

Re-arranging for r

And substituting into the previous equation

Solving for T,

So we see that the period is:
- proportional to the charge and the magnetic field
- inversely proportional to the mass and the square of the speed
So the following will increase the period of the particle's motion:
Increasing its charge
Increasing the field strength
Answer:
pumpkin
Explanation:
watermelon and pumpkins are close to shape and size