Question

a 10 kg Block with initial velocity 10 slides 10 metre across horizontal surface and come to rest it take to seconds to stop stopping force acting on the block about is
1)5N
2)10N
3)25N
4)50N​

Answer 1

Gɪᴠᴇɴ :-

• Mass(m) = 10kg
• Initial velocity (u) = 10m/s
• Final velocity (v) = 0 m/s (At rest)
• Distance covered (s) = 10m

Tᴏ ғɪɴᴅ :-

• Force(F)

sᴏʟᴜᴛɪᴏɴ :-

On applying 3rd equation of motion, we get,

➠ v² - u² = 2as

➭ (0)² - (10)² = 2 × a × 10

➭ -100 = 20a

➭ a = -100/20

➭ a = -5 m/s²

Hence,

• Acceleration (a) = -5m/s²

➦Negative sign shows deceleration or retardation.

Now,

We know that,

➠ Force (F) = Mass(m) × Acceleration (a)

➠ F = m × a

➭ F = 10 × -5

➭ F = -50 N

➦ Negative sign shows that Force must be applied in opposite direction of motion.

Hence,

• Option(4) 50N is correct