Answer:
Explanation:
a )
change in the gravitational potential energy of the bear-Earth system during the slide = mgh
= 45 x 9.8 x 11
= 4851 J
b )
kinetic energy of bear just before hitting the ground
= 1/2 m v²
= .5 x 45 x 5.8²
= 756.9 J
c ) If the average frictional force that acts on the sliding bear be F
negative work done by friction
= F x 11 J
then ,
4851 J - F x 11 = 756.9 J
F x 11 = 4851 J - 756.9 J
= 4094.1 J
F = 4094.1 / 11
= 372.2 N
Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.
Answer:
21870.3156 N
Explanation:
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
g = Acceleration due to gravity = 1.6 m/s²
Equation of motion
The acceleration of the craft should be 1.02234 m/s²
Weight of the craft
Thrust
The thrust needed to reduce the velocity to zero at the instant when the craft touches the lunar surface is 21870.3156 N
<h2>
Option 1 is the correct answer.</h2>
Explanation:
Power of heater, P = 1790 W
Time used, t = 24 hours = 24 x 60 x 60 = 24 x 3600 s
We have the equation
We need to find energy,
Substituting
Energy = 1790 x 24 x 3600 J
Option 1 is the correct answer.
Answer:
m = 5 [mg]
Explanation:
We must remember that the definition of linear momemtum is defined as the product of mass by distance.
P = m*v
P = momentum = 40 [mg*m/s]
m = mass [mg]
v = velocity = 8 [m/s]
Now clearing m:
m = P/v
m = 40/8
m = 5 [mg]