Answer:
Deceleration of 0.075m/s²
Explanation:
Given parameters:
Initial velocity = 5m/s
Time = 40s
Final velocity = 2m/s
Unknown:
The jogger's acceleration = ?
Solution:
To solve this problem, we use;
a =
a is the acceleration
v is the final velocity
u is the initial velocity
t is the time taken
a = = - 0.075m/s²
Answer:
The average current I supplied to the cars motor is 0.225 Amperes.
Explanation:
The mass of the toy car is given as, m = 0.6 kg
The toy car operates at a steady speed of, v = 3.43 m/s.
It achieves the steady speed after a time, t = 5.69 seconds.
The total kinetic energy of the car is given by,
E =
= 0.5 × 0.6 ×
= 3.53 Joules
Since the efficiency of the motor is 30.6% = 0.306
The electrical energy equivalent is supplied to motor = .
The electrical energy is given by P × t = I × V × t = 11.54 Joules
P is the electric power where P = I × V where V is the voltage of the cell and is the average current, I.
Therefore we can write I × 9 × 5.69 = 11.54 Joules.
So the average current I = = 0.225 Amperes.
Answer:
Option (C) is correct.
Explanation:
Assuming that the hiker starts walking from the origin O as shown in the figure.
First, he walks 200 m west to point A (say), then he walks 100 m north to the final point B (say) as shown in the figure.
The final point B is in the north-west direction, therefore, the resulting point is in the north-west direction.
Hence, option (C) is correct.
