Question

A tension of 6000 N is experienced by the elevator cable of an elevator moving upwards with an

acceleration of 2 m/s2

. What is the mass of the elevator?

2. From the same point at height H above the ground, two stones simultaneously travel in

vertically opposite directions. The first stone is thrown upwards, with a velocity of 50 m/s., while

the second one is released. What will be the velocity of the second stone when the first stone is

at the highest point?

3. The numerical ratio of displacement to distance for a moving object is always less than 1. State

whether True or False and justify your answer

4. The tips of the blades in a food blender are moving with a speed of 20 m/s in a circle that has a

radius of 0.06 m. How much time does it take for the blades to make one revolution?

5. What is the magnitude of electrical force of attraction between an iron nucleus (26 protons) and its

innermost electron if the distance between them is 1.0 x 10-12 m?

6. A car traveling at a certain speed notices an obstacle in the front and suddenly applies brakes. While

coming to a stop, it skids for 92 m long on the highway. Assuming a deceleration of 7 m/s2

, estimate the

speed of the car just before braking.

7. A cab is moving with a constant velocity of 90 km/h towards Bangalore except for a 30 min rest

stop. If the average velocity is 75 km/h towards Bangalore, how long does the trip take?

8. Elements in a given period of the periodic table contain same number of –

a. Protons b. Neutrons c. Electrons in the outermost shell d. None of these

9. In which set below do elements exhibit the most similar chemical properties

a. N, O, F b. Li, Na, K c. Al, Si, P d. Fe, Al, Ne

10. Which ion has the largest radius?

a. Na+

b. K

+

c. Mg2+ d. Ca2+​

Answer 1

Answer:

1) 3000kg:

force = mass× acceleration

6000n = x × 2m/s^2

x= 6000/2= ans 3000KG

3) displacement=< distance