6 J is the impulse caused by the change in velocity of 2 kg box from 2 m/s to 5 m/s.
Answer:
The magnitude of impulse is 6 J.
Explanation:
Impulse is the force acting on any object for a given time interval. As force is equal to the product of mass and acceleration and acceleration is the rate of change of velocity with time. Then the product of force with time interval will be equal to the product of mass with change in velocity.
F = m a = 
FΔt = mΔv
Impulse = FΔt=mΔv
As the mass of box is given as 2 kg and the velocity changes from 2 m/s to 5 m/s, then the impulse = 2 × (5-2) = 2 ×3 =6 J
So 6 J is the impulse caused by the change in velocity of 2 kg box from 2 m/s to 5 m/s.
Answer:
1) F = 24 N
2) Distance = 1 m
Explanation:
We are given;
Mass; m = 120 g = 0.12 kg
Initial velocity; u = 20 m/s
Final velocity; v = 0 m/s since it came to rest.
Time; t = 0.1 s
We can calculate acceleration from Newton's first equation of motion;
a = (v - u)/t
a = (0 - 20)/0.1
a = -200 m/s²
1) magnitude of the resistance will be;
F = ma
F = 0.12 × (-200)
F = -24 N
Since, we are dealing with the magnitude, we will take the absolute value. Thus, F = 24 N
2) To find the distance moved by the bullet, we know that;
Distance = Average speed × time
Thus;
Distance = ((v + u)/2) × t
Distance = ((0 + 20)/2) × 0.1
Distance = 1 m
To calculate the speed and velocity of the Ann`s we use the formula,
Here, d is distance and t is time and v if we take it with direction then it is called velocity and if we take it without the direction then it is called speed.
Given 
and 
.
Substituting these values in above equation we get
As Ann walked towards south direction therefore, Ann`s velocity is 3 mi/h south and her speed is 3 mi/h .
Answer:
Velocity of airplane is 500 km/h
Velocity of wind is 40 km/h
Explanation:
= Velocity of airplane in still air
= Velocity of wind
Time taken by plane to travel 1150 km against the wind is 2.5 hours
Time taken by plane to travel 450 km against the wind is 50 minutes = 50/60 hours
Subtracting the two equations we get
Applying the value of velocity of wind to the first equation
∴ Velocity of airplane in still air is 500 km/h and Velocity of wind is 40 km/h
