The position vector of a particle changes with time according to the relation r → t = 15 t 2 i ^ + 4 -…

The position vector of a particle changes with time according to the relation r→t=15t2i^+4-20t2j^. What is the magnitude of the acceleration at t=1?
  1. 40
  2. 25
  3. 100
  4. 50

Solution

r→=15t2i^+4-20t2j^
v→=30 ti^-40t j^
a→=30 i^-40j^
At t=1 ,
a→=30 i^-40j^
a→=50

Asked in: JEE Main 2019 (09 Apr Shift 2)

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