Answer:
The average force that the shooter must exert to prevent the weapon from moving is 21.7 Newtons.
Explanation:
m=33g=0,033kg
V= 342 m/seg
115 bullets/min= 1 bullet every 0.52 seconds.
By the principle of momentum and amount of movement we have to:
F*t=m*V
F= (m*V)/t
F= (0.033kg * 342 m/s) / 0.52 sec
F= 21.7 Newtons
Inertia is the tendency of an object to resist a change in its motion.
If the surface is perfectly frictionless AND level ... no ups and downs ... then the puck never slows down or stops. There's nothing to make it do so. (Notice that "perfectly frictionless" means no air resistance either.)
Question:
Calculate the change in internal energy of the following system: A balloon is cooled by removing 0.652 kJ of heat. It shrinks on cooling, and the atmosphere does 389 J of work on the balloon. Express your answer in Joules (J)
Answer:
-263J
Explanation:
Though its difficult and infact impossible to measure the internal energy of a system, the change in internal energy ΔE, can however be determined. This change when it is accompanied by work(W) and transfer of heat(Q) in or out of the system, can be calculated as follows;
ΔE = Q + W ----------------(i)
Q is negative if heat is lost. It is positive otherwise
W is negative if work is done by the system. It is positive otherwise.
From the question;
Q = -0.652kJ = -652J {the negative sign shows heat loss}
W = +389J {the positive sign shows work done on the system(balloon)}
<em>Substitute these values into equation (i) as follows;</em>
ΔE = -652 + 389
ΔE = -263J
Therefore the change in internal energy is -263J
PS: The negative sign shows that the process is exothermic. This means that the system (balloon) lost some energy to the environment.