Answer:
The time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s is 0.84 seconds.
Explanation:
Given that,
Acceleration of the car, 
Initial speed of the car, u = 24.6 m/s
Final speed of the car, v = 26.8 m/s
We need to find the time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s. The acceleration of an object is given by :
t = 0.84 seconds
So, the time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s is 0.84 seconds. Hence, this is the required solution.
Answer: 750 N
Explanation:
The net force is 1200 - 450 = 750 N
As we are told the speed is constant, then this force must be increasing the car's potential energy by climbing a hill.
F = mgsinθ
If we knew the car mass, we could find the hill slope angle.
If we knew the hill slope angle, we could find the car mass.
Answer:
vi) Double the current in the wire, and double the number of turns in the 20-cm long solenoid
Explanation:
The magnetic field inside the solenoid and the current flowing in the coil of solenoid are related to each other by the following equation
B₀=μ₀nI₀
Where,
B₀ is the magnetic field in the middle of solenoid
n is the number of turns in the coil of solenoid
I₀ is the current flowing in the coil of solenoid
In the above equation, as μ₀ is a constant so the magnetic field will be directly proportional to the number of turns multiplied by the current. So, changing the radius of the coil or length of the coil will have no effect on the magnetic field.
As we have to increase the magnetic field by 4 times, we need to double the current as well as the number of turns as mentioned in the option vi.
You have to move your foot to stop the car so I guess that would be considered work by moving your foot
