以火车以2m/s的初速度，0.5m/s²的加速度做匀加速直线运动，求(1)火车在第3s末的速度是多少(2)在前4s
1个回答
展开全部
1.
v1 = v0 + at1 = 2m/s + 0.5m/s2 × 3s = 3.5m/s
2.
s2 = v0t2 + 1/2a（t2^2） = 2 × 4 + 1/2 × 0.5m/s2 × ( 4s^2 ) = 12m
v拔 = s2 ÷ t2 = 12m ÷ 4s = 3m/s
3.
s3 = v0t3 + 1/2a (t3^2) = 2 × 5 + 1/2 × 0.5m/s2 × ( 5s^2 ) = 16.25m
Δs1 = s3 - s2 = 16.25m - 12m = 4.25m
4.
s4 = v0t4 + 1/2a (t4^2) = 2 × 8 + 1/2 × 0.5m/s2 × ( 8s^2 ) = 32m
Δs2 = s4 - s2 = 32m - 12m = 20m
v1 = v0 + at1 = 2m/s + 0.5m/s2 × 3s = 3.5m/s
2.
s2 = v0t2 + 1/2a（t2^2） = 2 × 4 + 1/2 × 0.5m/s2 × ( 4s^2 ) = 12m
v拔 = s2 ÷ t2 = 12m ÷ 4s = 3m/s
3.
s3 = v0t3 + 1/2a (t3^2) = 2 × 5 + 1/2 × 0.5m/s2 × ( 5s^2 ) = 16.25m
Δs1 = s3 - s2 = 16.25m - 12m = 4.25m
4.
s4 = v0t4 + 1/2a (t4^2) = 2 × 8 + 1/2 × 0.5m/s2 × ( 8s^2 ) = 32m
Δs2 = s4 - s2 = 32m - 12m = 20m
本回答由提问者推荐
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
