Q 48

A particle moves along a circular path having a radius of 2.0 m.At an instant when the speed of the particle is equal to 3.0 m/s and changing at the rate of 5.0 m/s^{2},what is the magnitude of the total acceleration of the particle?
A)7.5 m/s^{2}
B)6.0 m/s^{2}
C)5.4 m/s^{2}
D)6.7 m/s^{2}
E)4.5 m/s^{2}

Q 49

A car travels in a flat circle of radius R.At a certain instant the velocity of the car is 20 m/s north,and the total acceleration of the car is 2.5 m/s^{2} 37 south of west.Which of the following is correct?
A)R = 0.40 km,and the car's speed is decreasing.
B)R = 0.20 km,and the car's speed is decreasing.
C)R = 0.20 km,and the car's speed is increasing.
D)R = 0.16 km,and the car's speed is increasing.
E)R = 0.16 km,and the car's speed is decreasing.

Q 50

A car travels in a flat circle of radius R.At a certain instant the velocity of the car is 24 m/s west,and the total acceleration of the car is 2.5 m/s^{2} 53 north of west.Which of the following is correct?
A)R = 0.29 km,and the car's speed is increasing.
B)R = 0.23 km,and the car's speed is decreasing.
C)R = 0.23 km,and the car's speed is increasing.
D)R = 0.29 km,and the car's speed is decreasing.
E)R = 0.29 km,and the car's speed is constant.