Answer:
945 j
Explanation:
You have just given the ball kinetic energy, which is given by the following equation:
KE= 1⁄2 m v2 = 1⁄2 (2.1 kg)(30 m/s)2 = 945 Joules
Answer:
The velocity of mass 2m is 
Explanation:
From the question w are told that
The mass of the billiard ball A is =m
The initial speed of the billiard ball A = 
=1 m/s
The mass of the billiard ball B is = 2 m
The initial speed of the billiard ball B = 0
Let the final speed of the billiard ball A = 
Let The finial speed of the billiard ball B = 
According to the law of conservation of Energy
Substituting values
Multiplying through by 
According to the law of conservation of Momentum
Substituting values
Multiplying through by 
making subject of the equation 2
Substituting this into equation 1
Multiplying through by 
Answer:
v = 21.25 km/h
The average velocity is 21.25km/h
Explanation:
Average velocity = total displacement/time taken
v = d/t
Given;
A car travels 50 km in 25 km /h
d1 = 50km
v1 = 25km/h
time taken = distance/velocity
t1 = d1/v1
t1 = 50/25 = 2 hours
and then travels 60km with a velocity 20 km/h
d2 = 60km
v2 = 20km/h
t2 = d2/v2 = 60/20
t2 = 3 hours
and then travels 60km with a velocity 20 km/h in the same direction
d3 = 60km
v3 = 20km/h
t3 = d3/v3 = 60/20
t3 = 3 hours
Average velocity = total displacement/total time taken
v = (d1+d2+d3)/(t1+t2+t3)
v = (50+60+60)/(2+3+3)
v = 170/8
v = 21.25 km/h
The average velocity is 21.25km/h
The formula for kinetic energy is equal to 1/2mv^2, where "m" is the mass of the object (in kilograms) and "v" is equal to the velocity of the object (in meters per second). To calculate the speed, simply plug in the values and solve.
KE = 0.5mv^2
304 J = 0.5(0.3 kg)v^2 -mass converted from grams to kilograms
v = 45.02 m/s
The baseball is travelling about 45.02 meters per second.
Hope this helps!
I believe this would be an example of positive acceleration as the initial velocity of the rocket is less than the final velocity, indicating that the rocket is accelerating and thus is positive.
