একটি গাড়ির বেগ ৩০ মি./সে. থেকে সুষমভাবে হ্রাস পেয়ে ৫ সে. পর ১০ মি./সে. হলে গাড়িটির ত্বরণ কত মি./সে.^২?
To solve this problem, let's analyze it step-by-step:

Step-1: we know, acceleration a = dv/dt, where dv = change in velocity, dt = time over which the change occurs

Step-2: So, The initial velocity 30 meters per second.

Step-3: The final velocity is 10 meter per second.

Step-4:  So change in velocity,dv is = (10-30) meter per second = -20 meters per second.

Step-5: Given time period dt = 5 second. So a = dv/dt = -20/4 = -4 meter per second square

#Answer: -4 meter per second square