Density is mass divided by volume. rho=m/v. So, v=m/rho. In frank's case this is 80/8 = 10 cm^3.
Answer:
p = 4000 kg-m/s
Explanation:
Given that,
The mass of a truck, m = 200 kg
Speed of the truck, v = 20 m/s
We need to find the momentum of the truck. The formula for momentum is given by :
p = mv
so,
So, the momentum of the truck is equal to 4000 kg-m/s.
Let the mass of the person be m. Total momentum is conserved (because the exterior forces on the system are balanced), especially the component in the vertical direction.
Given that,
Mass of gallon is M
Let man mass be m
Velocity of man is v
Let velocity if ballot be Vb
When the person begin to move we have
Conservation of momentum
mv + MVb=0
MVb=-mv
Vb= -(m/M) v
Given that the mass of man is less than mass of balloon. i.e. m<M
So, if m<M, then, m/M <1
Therefore, .
Vb= -(m/M) v
Vb< -v
This implies that the velocity of balloon is less than the velocity of man and if is also moving in opposite direction
So the man is moving upward, then the balloon is moving downward and it's velocity is less than the velocity of man,
The answer is C
Down with a speed less than v
Answer:
Explanation:
= normal force acting on the coin
Normal force in the upward direction balances the weight of the coin, hence
= frequency of rotation
Angular velocity of turntable is hence given as
= distance from the axis of rotation
= minimum coefficient of static friction
static frictional force is given as
The static frictional force provides the necessary centripetal force , hence
Centripetal force = Static frictional force
Answer:
800 Watts
Explanation:
Power = Work/time
Working in SI units, Power = Watts, Work = Joules, Time = seconds.
Power = 2240J/2.8s = 800 Watts.
