Question: i need assistance with these10andnbspandnbspa boy walks 155 m at...

i need assistance with these

10.  A boy walks 155 m at a speed of 3.5 m/s and then runs for 100 m at 8.2 m/s along a straight line. Calculate his average velocity. 

 

(a) 3.0 m/s 

(b) 4.5 m/s 

(c) 4.0 m/s 

(d) 2.5 m/s 

(e) 1.0 m/s 

(f)  12.0 m/s 

 

 

 

11.  A boat can accelerate from 2 to 21 km/h in 10 s. How far has the boat travelled in this time ? 

 

(a) 32 m 

(b) 30 m 

(c) 12 m 

(d) 25 m 

(e) 35 m 

(f)  22.5 m 

 

12.  A Porsche travelling at a constant velocity of 32 m/s passes a Mini parked on the side of the road. When the Porsche is 50 m ahead, the Mini starts accelerating uniformly at 3.5 m/s². How fast is the Mini travelling when it reaches the Porsche ?. 

 

(a) 36 m/s 

(b) 45 m/s 

(c) 12 m/s 

(d) 69 m/s 

(e) 78 m/s 

(f)  112 m/s 

 

 

 

 

 

 

13.  Three vectors are given by A = 3i, B = -1i +1j and C = 4j. Find the magnitude of the resultant vector. 

 

(a) 6.3 

(b) 5.4 

(c) 5.0 

(d) 2.3 

(e) 1.1 

(f)  0.5