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Important Mcqs 1-10 (in Hindi)
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10 important MCQs on Motion in a straight line.

## Tamanna Chaudhary is teaching live on Unacademy Plus

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a man in a ballon rising vertically with an acc of4.9 released a ball 2sec after the ballon is let go from the ground the greatest height above the ground reached by the ball [g =9.8]
Step 1- We need to calculate the upward velocity of the ballon after 2seconds of It's let go- Use equation v= u+at. put u=0, t=2 and a= 9.8ms^-2 to get v= 9.8 m/s in upward direction.
Step 2- Calculate the distance moved by the balloon in these 2 seconds to see from what height the ball has been dropped - Use the equation, S= ut + 1/2(at^2) put u=0, a=4.9 m/s^2, t= 2s. We will get S= 9.8m
Step 3- Now as we know the initial velocity of the ball (in the upward direction) and height from which it was thrown down, calculate the velocity with which it hit's the ground- v^2- u^2 =2as. Be careful about the sign conventions here. Substitute u = -9.8m/s, S = (9.8m) and a=g to get v= (underroot 3)g
Step 4- Now we know the velocity with which the ball hit the ground, and we know the value to gravitational acceleration. so use the equation again- v^2- u^2= 2as Substitute the values along with sign conventions- u= - (underroot 3) g a= g to get S= -14.7m, where negative sign signifies the distance travelled in upward direction
Ashish Tiwary
a year ago
Thanks mam
Ashish Tiwary
a year ago
Mam step 1 me a=4.9 use karnege n & a=4.9 sirf upward motion ke liye hi use krenge n
maam ques three me particle rest se start koya toh uski initial velocity 100 kaise hui???plz
By using v^2 - u^2 = 2as equation, aapko S ki wo value nikalni hai jo object cover karega from time t to t+1, iska matlab hai ki aap is equation mein initial velocity loge time t wali and final velocity loge time t+1 wali. Agar aapko distance travelled by the toby in total time t+1s pucha hota tab aap initial velocity ko zero lete, lekin humein yahan S ki value puri journey ki nahi puchi hai sirf t se t+1 time ke beech wali puchi hai.
Ma'am question No 19 my app ny kesy distances find kiye Han Samjh nhi aye.. Kindly guide
My
mam question 9 ek baar explain kar dijiye plz
Musa Khan
4 months ago
Firstly that ratio of s1,s2.... given is the distance travelled in seconds like s3 is distance travelled in 3 seconds whereas s'3 is the distance travelled in particularly 3rd second.
Musa Khan
4 months ago
Firstly that ratio of s1,s2.... given is the distance travelled in seconds like s3 is distance travelled in 3 seconds whereas s'3 is the distance travelled in particularly 3rd second.
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