The conservation of momentum states that the total momentum in a system is constant if there is no external force acting on the system. The total momentum in the gun bullet system is 0 so it must stay that way.
The momentum of the bullet is mv = 0.015*500=7.5
The momentum of the gun must be the same to keep the total momentum of the system equal to zero, so we know that p = 7.5 for the gun.
Substituting this in we get:
7.5=3.1x
x=7.5/3.1
x=2.42
So the speed of the gun is 2.4m/s.
The text does not specify whether the resistance R of the wire must be kept the same or not: here I assume R must be kept the same.
The relationship between the resistance and the resistivity of a wire is

where

is the resistivity
A is the cross-sectional area
R is the resistance
L is the wire length
the cross-sectional area is given by

where r is the radius of the wire. Substituting in the previous equation ,we find

For the new wire, the length L is kept the same (L'=L) while the radius is doubled (r'=2r), so the new resistivity is

Therefore, the new resistivity must be 4 times the original one.
Answer:
0.0928km/min (4dp)
Explanation:
To find the jogger's speed in km per minute, we just need to divide the number of km jogged by the time in minutes it took to jog that distance. This will give us the distance they jogged every minute which is their speed.
4km in 32 minutes:
4/32 = 0.125km/min
2km in 22 minutes:
2/22 = 0.091 (3dp)km/min
1km in 16 minutes:
0.0625km/min
Now to find the average speed of these 3 speeds, we just add them all together and divide by how many values there are (3 values).
Average (mean) = 
Average = 0.2785/3
Average speed of jogger = 0.0928 (4dp) km/min
Hope this helped!
iIn this case the mass of a body cannot be considered to be concentrated at the centre of mass of the body for the purpose of computing the rotational motion
Therefore the answer is False
Answer:
A) 17.7 m/s
B) 15.98 m
C) Zero
E) 9.8 m/s²
Explanation:
given information
distance, h = - 34 m
time, t = 5 s
A) What is the initial speed of the egg?
h - h₀ = v₀t -
t², h₀ = 0
- 34 = v₀ 5 - \frac{1}{2} 9.8 5²
- 34 = 5 v₀ - 122.5
v₀ = 122.5 - 34/5
= 17.7 m/s
B) How high does it rise above its starting point?
v² = v₀² - 2gh
v = 0 (highest point)
2gh = v₀²
h = v₀²/2g
= 17.7²/2 (9.8)
= 15.98 m
C) What is the magnitude of its velocity at the highest point?
v = 0 (at highest point)
E) What are the magnitude and direction of its acceleration at the highest point?
g= 9.8 m/s², since the egg is moved vertically, the acceleration is the same as the gravitational acceleration.